“Dr. Smith, what is this?” “That is a time machine, Sally.

　　With this machine, we can go back in time.”

　　“Wow! Can we try it?”

　　“Of course! Where do you want to go?”

　　“I want to see the dinosaurs.”

　　“No problem. Let’s go! Hop in, Tim! Hop in, Sally!”

　　“Here we are. One million years ago.”

　　“Wow! It looks very different. Everything is so big.”

　　“Yes, many of the plants are very big.”

　　“Dr. Smith, I don’t see the dinosaurs.” “Look up.”

　　“Wow! It is huge and scary looking. Will it eat me?”

　　“No, he will not eat you, Tim. He is a plant-eater.”

　　“Whew! That’s good.”

　　“Besides, he is only a baby. Look over there.

　　That is his mother.” “WOW!”

　　“That dinosaur sure is big.”

　　“That is one of the biggest dinosaurs ever, Sally.

　　It is called a Brontosaurus. It weighs more than28 tons and is over 30 meters long.”

　　“I hope he does not step on me.”

　　“That would be very bad.”

　　“Let’s explore more! But be careful.”

　　“Look at that dinosaurs. He is smaller than the other ones.”

　　“Yes, he is an Iguanodon. He is a plant-eater too.”

　　“If he is a plant-eater, he will not hurt me.

　　Hello, Iguanodon. How are you today?”

　　“Tim, watch out!”

　　“That was close. He almost hit with his tail.”

　　“Yes, the Iguanodon has a very powerful tail. He can usehis tail when he is attacked.” “He also uses it to hit small

　　boys.” “Ha! Ha! Ha!” “Maybe we should leave him alone.”

　　“That’s a good idea, Tim.”

　　“Ah! Look over there. Look at that dinosaur.

　　He has a very large head. What’s his name, Dr. Smith?”

　　“He is a Triceratops. His head is very big